function drupal_prepare_form

Prepares a structured form array by adding required elements, executing any hook_form_alter functions, and optionally inserting a validation token to prevent tampering.

Parameters

$form_id: A unique string identifying the form for validation, submission, theming, and hook_form_alter functions.

$form: An associative array containing the structure of the form.

Related topics

File

includes/form.inc, line 281

Code

function drupal_prepare_form($form_id, &$form) {
  global $user;
  $form['#type'] = 'form';
  if (!isset($form['#post'])) {
    $form['#post'] = $_POST;
    $form['#programmed'] = FALSE;
  }
  else {
    $form['#programmed'] = TRUE;
  }

  // In multi-step form scenarios, this id is used to identify
  // a unique instance of a particular form for retrieval.
  if (isset($form['#build_id'])) {
    $form['form_build_id'] = array(
      '#type' => 'hidden',
      '#value' => $form['#build_id'],
      '#id' => $form['#build_id'],
      '#name' => 'form_build_id',
    );
  }

  // If $base is set, it is used in place of $form_id when constructing validation,
  // submission, and theming functions. Useful for mapping many similar or duplicate
  // forms with different $form_ids to the same processing functions.
  if (isset($form['#base'])) {
    $base = $form['#base'];
  }

  // Add a token, based on either #token or form_id, to any form displayed to
  // authenticated users. This ensures that any submitted form was actually
  // requested previously by the user and protects against cross site request
  // forgeries.
  if (isset($form['#token'])) {
    if ($form['#token'] === FALSE || $user->uid == 0 || $form['#programmed']) {
      unset($form['#token']);
    }
    else {
      $form['form_token'] = array(
        '#type' => 'token',
        '#default_value' => drupal_get_token($form['#token']),
      );
    }
  }
  else {
    if ($user->uid && !$form['#programmed']) {
      $form['#token'] = $form_id;
      $form['form_token'] = array(
        '#id' => form_clean_id('edit-' . $form_id . '-form-token'),
        '#type' => 'token',
        '#default_value' => drupal_get_token($form['#token']),
      );
    }
  }
  if (isset($form_id)) {
    $form['form_id'] = array(
      '#type' => 'hidden',
      '#value' => $form_id,
      '#id' => form_clean_id("edit-{$form_id}"),
    );
  }
  if (!isset($form['#id'])) {
    $form['#id'] = form_clean_id($form_id);
  }
  $form += _element_info('form');
  if (!isset($form['#validate'])) {
    if (function_exists($form_id . '_validate')) {
      $form['#validate'] = array(
        $form_id . '_validate' => array(),
      );
    }
    elseif (function_exists($base . '_validate')) {
      $form['#validate'] = array(
        $base . '_validate' => array(),
      );
    }
  }
  if (!isset($form['#submit'])) {
    if (function_exists($form_id . '_submit')) {

      // We set submit here so that it can be altered.
      $form['#submit'] = array(
        $form_id . '_submit' => array(),
      );
    }
    elseif (function_exists($base . '_submit')) {
      $form['#submit'] = array(
        $base . '_submit' => array(),
      );
    }
  }
  foreach (module_implements('form_alter') as $module) {
    $function = $module . '_form_alter';
    $function($form_id, $form);
  }
  $form = form_builder($form_id, $form);
}